Abstract
Understanding of quantum limit in low dimensional devices helps to develop the new device types same as Carbon Nanotube Field Effect Transistor (CNTFET) and Naonowire. For each dimensionality the limitations on carrier drift velocity due to the high-field streaming of otherwise randomly velocity vector in equilibrium is reported. The results are based on the asymmetrical distribution function that converts randomness in zero-field to streamlined one in a very high electric field. The ultimate drift velocity for all dimensions is found to be appropriate thermal velocity for a nondegenerately doped sample of silicon, increasing with the temperature, but independent of carrier concentration. However, the ultimate drift velocity is the Fermi velocity for degenerately doped silicon increasing with carrier concentration but independent of the temperature.
Highlights
The quest for high-speed devices and circuits for Ultra-Large-Scale-Integration (ULSI) is continuing
That was the push for Gallium Arsenide (GaAs) considering that the mobility of an electron in GaAs is 5-6 times higher than that of an electron in silicon
At low temperature, carriers follow the degenerate statistics and their velocity is limited by appropriate average of the Fermi velocity that is a function of carrier concentration
Summary
The quest for high-speed devices and circuits for Ultra-Large-Scale-Integration (ULSI) is continuing. As development of the devices to nanoscale dimensions continued it became clear that the saturation velocity plays a predominant role. The higher mobility brings an electron closer to saturation as a high electric field is encountered, but saturation velocity remains the same no matter what the mobility. There is no clear consensus on the interdependence of saturation velocity on low-field mobility that is scattering-limited. There are a number of theories of high-field transport to answer this interdependence. Rigor of mathematics and a number of clandestine parameters that are used in these simulations present a foggy picture of what controls the ultimate saturation of drift velocity. The outcome that higher mobility leads to higher saturation is not supported by experimental observations prompting our careful study of the process controlling the ultimate saturation. The fundamental processes that limit drift velocity are delineated
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Malaysian Journal of Fundamental and Applied Sciences
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
